In the early 1900s, psychiatrist Dr. Wehr conducted an intriguing experiment into sleep. He had a group of people plunged into darkness for 14 hours a day with no way to tell the time. The idea was that without the disturbance of electrical lights, the natural sleep cycle would reveal itself. By week #4, each of the subjects slept four hours, awoke for two, then slept for another four hours. Each of them slept biphasically. Each of them slept polyphasically. [1] [2]
This experiment, combined with historian Roger Ekirch's views on sleep cycles in the pre-industrial era, heavily suggest that monophasic isn't our natural sleep cycle. If this is the case, perhaps insomniacs don't have something wrong with them-- they are just more in tune with the natural cycle. Lying awake at night is a norm. With monophasic, we're sleeping terribly, terribly wrong.